Longitudinal joint densities are typically higher than the density of the mat. What is the average percentage difference?

Longitudinal joint densities being higher than the density of the mat can be attributed to the construction process and the proper compaction techniques used during placement. The average percentage difference, which is generally accepted to be between 1-6%, indicates that the compaction of the material at the longitudinal joint is often more effective compared to the mat itself.

This increased density at the joint is crucial for ensuring a strong, durable pavement that can better withstand stresses, such as those from traffic loads and environmental conditions. The joint is a critical area of potential weakness, and achieving higher density helps minimize the risk of cracking and other performance issues in that region over time. Understanding this percentage difference aids inspectors and engineers in evaluating the quality of asphalt installations and ensuring compliance with specified compaction standards.